Field-scale performance of biochar-amended soil covers for landfill methane oxidation
Field-scale performance of biochar-amended soil covers for landfill methane oxidation
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DOI：
10.1007/s13399-021-01487-w
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发表时间：
2021-04
影响因子：
4
通讯作者：
K. Reddy;Erin N. Yargicoglu;Jyoti K. Chetri
中科院分区：
文献类型：
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作者：
K. Reddy;Erin N. Yargicoglu;Jyoti K. Chetri
对三种生物炭改性土壤覆盖物（2%、10%和100%生物炭改性土壤）以及土壤控制覆盖物进行了现场验证，并在一个活性城市固体废物（MSW）填埋场的中间覆盖物中进行了现场验证，同时进行了实验室研究，评估了生物炭增强覆盖物土壤中甲烷（CH4）氧化的效果。在相关实验室研究中评估的模拟三种覆盖设计的试验场安装之前，对基线ch4排放和预先存在的场地条件进行了表征。在8个月的监测期内，通过静室测量地表ch4通量和采样不同深度的土壤孔隙气体来评估覆盖性能。试验点的地表通量表现出广泛的空间变异性，在一次调查中，一个地点的通量为100 ~ 1100 g CH4m−2day−1。在田间试验结束后，通过对挖掘出的土壤岩心亚样品进行批量测定，确定了ch4氧化的潜在速率，范围为~1 ~ 350 μg CH4g−1day−1。废弃物的异质性导致试验田的ch4负荷不均匀。土壤对照试验田ch4负荷较高，生物炭改性试验田ch4负荷显著降低。结果表明，土壤对照试验区的ch4氧化速率（257 ~ 289 μg CH4g−1day−1）高于生物炭处理试验区。同样，土壤对照区甲烷氧化菌的相对丰度也较高，且与ch4氧化速率呈正相关。添加10%生物炭的试验田ch4负荷接近土壤对照的25%，但ch4氧化速率（260 μg CH4g−1day−1）仍与土壤对照相当，说明生物炭对提高ch4氧化速率有一定的作用。环境和ch4暴露条件对试验田微生物群落组成有影响，显示甲单菌属和crenothrixspp等I型甲烷营养菌属占优势。总体而言，废弃物的异质性导致每个试验区的ch4暴露条件不均匀，难以明确量化生物炭改性对ch4氧化速率的影响。
A field validation of three biochar-amended soil covers (2%, 10%, and 100% biochar-amended soils) along with a soil control cover was conducted within the intermediate cover of an active municipal solid waste (MSW) landfill in conjunction with laboratory studies evaluating the effect of biochar in enhancing methane (CH4) oxidation in cover soils. Baseline CH4emissions and pre-existing site conditions were characterized prior to installation of test plots simulating three cover designs evaluated in related laboratory studies. Static chamber measurements of surface CH4fluxes and sampling of soil pore gas at different depths were conducted across the 8-month monitoring period to assess cover performance. Surface fluxes from the test plots exhibited wide spatial variability, with one location emitting fluxes > 1100 g CH4m−2day−1in one survey. Potential rates of CH4oxidation were determined in batch assays of exhumed soil core subsamples following termination of the field trial and ranged from ~1 to 350 μg CH4g−1day−1. The heterogeneity of the waste led to nonuniform CH4loads in the test plots. The soil control test plot was exposed to higher CH4loads and biochar-amended test plots were exposed to significantly lower CH4loads. As a result, the soil control test plot showed higher CH4oxidation rates (257–289 μg CH4g−1day−1) than the biochar-amended test plots. Similarly, the soil control plot also showed higher relative abundance of methanotrophs which was positively correlated with the CH4oxidation rates. The test plot with 10% biochar-amended soil experienced CH4loads nearly 25% of that in soil control and still showed CH4oxidation rates (260 μg CH4g−1day−1) comparable to that of soil control which showed the efficacy of biochar amendment in enhancing CH4oxidation rates. The environmental and CH4exposure conditions affected the microbial community composition in the test plots and showed the dominance of type I methanotrophic genus such asMethylomonasandCrenothrixspp. Overall, the waste heterogeneity led to nonuniform CH4exposure conditions at each test plot making it hard to distinctly quantify the effect of biochar amendment on CH4oxidation rates.